The ingredient in question contains N-nitrosodiethylamine (NDEA), "a substance that occurs nationally in certain foods, drinking water, air pollution, and industrial processes" and has been classified by the International Agency for Research on Cancer as a probable human carcinogen.

NDEA was manufactured by a factory in China called Zhejiang Huahai Pharmaceuticals, which has been linked to several recalls of blood pressure drugs dating back to July.

Lots of other blood pressure and heart medications such as valsartan, losartan, amlopidine and hydrochlorothiazide have also been recalled since July.

Hetero Labs, another factory in India, has also been linked to multiple recalls.

Prinston will only be recalling lots of irbesartan-containing products that contain NDEA above the acceptable intake levels released by the FDA.

"Patients who are on Irbesartan should continue taking their medication, until their pharmacist provides a replacement, or their doctor prescribes a different medication that treats the same condition as the risk of harm to a patient's health may be higher if the treatment is stopped immediately without any alternative treatment," the FDA statement said.